The invention relates to a wheel module for a vehicle with an electrically controlled braking system (EBS) for controlling the braking force on at least one wheel of the vehicle, and more particularly a wheel module which transmits an adjusting signal, computed thereby on the basis of a brake value and wheel specific signals transmitted thereto, to an actuator installed on the wheel for the adjustment of the braking force.
A wheel module of this type is disclosed, for example, in EP 0 467 112 (U.S. Pat. No. 5,255,962, which is incorporated herein by reference).
The known wheel module comprises part of an electrically controlled braking system which, in addition to the wheel modules, includes a central module and signal transmission devices, such as, for example, a brake signal transmitter. Such wheel module is assigned to a particular wheel of a vehicle. A signal representing the rotational speed of the wheel is produced by means of a speed sensor assigned to the wheel, and is transmitted to the wheel module assigned to the same wheel for evaluation. An electronic control system located in the wheel module, and including a microprocessor, calculates a speed signal based upon such evaluation, and transmits same via a data bus system. Several wheel modules, each of which emits a corresponding speed signal, are connected via the data bus system to the central module. The central module evaluates the speed signals received by the data bus system and, from this, calculates, for example, a vehicle reference speed which is required for an anti-lock brake system (ABS) regulation. This vehicle reference speed and, if applicable, additional calculation results required for an ABS regulation, are then sent back by the central module to the wheel modules, which then use the data for an ABS regulation on the wheels corresponding thereto.
Consequently, relatively large amounts of data must be exchanged via the data bus system among the modules connected to it.
It is therefore the object of the present invention to provide a wheel module and a braking system in which the need for data transfer is reduced.